The best part of this bus tour is that you will actually see Washington, D.C. Instead of annoying touristy voices telling you about the surrounding historical sites, you'll have to observe for yourself. What you'll see are real D.C. neighborhoods. What you'll hear are real D.C. residents. So open up the eyes and the ears and hop aboard.
1) Begin by walking to the Central D.C. public library - the Martin Luther King Library at 9th and G. There will be a bus sign nearby that says "42." A schedule will (probably) be posted on the poll. Hop aboard the bus going in the direction of Mount Pleasant. When you get on, pay $1.25 and get a transfer slip. This trip won't last more than 2 hours and with a transfer slip, you'll get home free.
2) Listen to the people on the bus. Pay attention to buildings and the neighborhoods, enjoy the ride.
3) My recommended first stop: DuPont Circle - get off anywhere around the circle. For a great bookstore (at least Monica Lewinsky thought so) head to Kramerbooks. For a used bookstore, check out Second Story books.
4) If you're hungry: Wrapworks is cheap. Other possibilities - Subway, a sushi place, lots of trendy places.
5) After you've spent a little time in DuPont, use your transfer slip to get back on the bus in the direction of Mount Pleasant.
6) Possible second stop: Get off and explore Adams Morgan. Lots of bars, coffee shops, African and Indian crafty-type stores. Also great Ethiopian food at Meskerem.
7) Better yet, stay on the bus and go to Mt. Pleasant, the Hispanic center of D.C. Get off at the end of the ride - in front of the Bestway market. Now here's where the adventure begins. If you're in the mood for a walk, start walking down Mt. Pleasant street, just watching people and stopping in to the occassional store. This is not a touristy place. No fancy markets, antique stores, or trendy shops. Mount Pleasant is a normal city neighborhood with 7-Elevens and small parks, and a diverse group of people. (BTW - please go during the daytime because Mt. Pleasant is a CITY neighborhood).
Notice that there are 42 bus stops the whole way back along Mt. Pleasant so if you get tired, just hop the bus. But while you're able, just enjoy walking and seeing the city and the people. Mt. Pleasant is a great street - if you're up for coffee/tea, check out Dos Gringos.
8) The trip back. The bus will stop in Metro Center (great if you want to take a Metro). Or go to the Chinatown area and ask the driver when you should get off to be closest to Chinatown. Walk along 7th Street towards Chinatown. You are the last remnants of Chinatown - in a few years, it will all be bought up by stores, like Urban Outfitters and Old Navy. So take it in, and grab some Chinese food.
When you're ready, you can go home via the Chinatown metro or hop back on the 42.
NEXT trip - try out the D2.
Start: Washington Metro Transit Authority Web Page - http://www.wmata.com/ to get a list of bus routes and bus schedules. For this trip, you'll need to follow the link to bus schedules. Then, click on the "42" route. The website provides a great map with the 42 bus schedule and bus route.